Central action of peripherally applied botulinum toxin type a on pain and dural protein extravasation in rat model of trigeminal neuropathy

Scientific paper - Original scientific paper

• Author: Boris Filipović
• Author: Ivica Matak
• Author: Lidija Bach-Rojecky
• Author: Zdravko Lacković
• Author's institution: University of Zagreb; School of Medicine
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Basic Medical Sciences

Abstract (english)

BACKGROUND:

Infraorbital nerve constriction (IoNC) is an experimental model of trigeminal neuropathy. We investigated if IoNC is accompanied by dural extravasation and if botulinum toxin type A (BoNT/A) can reduce pain and dural extravasation in this model. ----- METHODOLOGY/PRINCIPAL FINDINGS:

Rats which developed mechanical allodynia 14 days after the IoNC were injected with BoNT/A (3.5 U/kg) into vibrissal pad. Allodynia was tested by von Frey filaments and dural extravasation was measured as colorimetric absorbance of Evans blue - plasma protein complexes. Presence of dural extravasation was also examined in orofacial formalin-induced pain. Unilateral IoNC, as well as formalin injection, produced bilateral dural extravasation. Single unilateral BoNT/A injection bilaterally reduced IoNC induced dural extravasation, as well as allodynia (lasting more than 2 weeks). Similarly, BoNT/A reduced formalin-induced pain and dural extravasation. Effects of BoNT/A on pain and dural extravasation in IoNC model were dependent on axonal transport through sensory neurons, as evidenced by colchicine injections (5 mM, 2 µl) into the trigeminal ganglion completely preventing BoNT/A effects. ----- CONCLUSIONS/SIGNIFICANCE:

Two different types of pain, IoNC and formalin, are accompanied by dural extravasation. The lasting effect of a unilateral injection of BoNT/A in experimental animals suggests that BoNT/A might have a long-term beneficial effect in craniofacial pain associated with dural neurogenic inflammation. Bilateral effects of BoNT/A and dependence on retrograde axonal transport suggest a central site of its action.

• Keywords (english): Analgesics / administration & dosage; Animals; Botulinum Toxins, Type A / administration & dosage; Central Nervous System / drug effects; Disease Models, Animal; Dura Mater / drug effects; Dura Mater / metabolism; Injections, Intraperitoneal; Male; Nerve Tissue Proteins / metabolism; Pain / drug therapy; Rats; Rats, Wistar; Sensory Receptor Cells / drug effects; Trigeminal Nerve Diseases / drug therapy; Trigeminal Nerve Diseases / pathology
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review
• Publication version: Published version
• Journal title: PLoS One
• Numbering: vol. 7, no. 1, e29803
• p-ISSN: 1932-6203
• DOI: https://doi.org/10.1371/journal.pone.0029803
• URN:NBN: urn:nbn:hr:105:385498
• Publication: 2012-01-04
• Document URL: https://doi.org/10.1371/journal.pone.0029803
• Type of resource: Text
• Access conditions: Open access
• Created on: 2024-03-27 19:16:26